Rapid cycle radial draw former



April 14, 1959 P. F. MAIZE ETAL 2,881,821

RAPIID CYCLE RADIAL DRAW FORMER 4 Sheets-Sheet 1 Filed Sept. 3, 1957 April 14, 1959' P. F. MAIZE ET AL 2,881,821

7 RAPID CYCLE RADIAL DRAW FORMER Filed Sept. 3. 1957 v 4Sheets-Sheet 2 P. F. M AIZE ET AL RAPID CYCLE RADIAL DRAW FORMER April 14, 1959 4 Sheets-Sheet 5 Filed Sept. 5, 1957 Y N 3 Ti 1:5.

| I I JU r GD 77ILNVENTOR '2 f fi /lrram/fr April 14, 1959 P. F. MAlZ E ET AL 2,881,821

' RAPID CYCLE among. DRAW- FORMER I Filed Sept. 3, 1957 4 Sheets-Sheet 4 inventor K 1 PAUL F MA/ZE &

Al/duJT Yuma}, Ia

RAPID CYCLE RADIAL DRAW FORMER Paul F. Maize, Davisburg, Mich., and August Yurka, Jr., Cleveland Heights, Ohio, assignors to The Cyril Bath Company, Solon, Ohio, a corporation of Ohio Application September 3, 1957, Serial No. 681,695 7 Claims. (Cl. 153-40) This invention relates to a radial draw former in which stock is formed progressively from one end toward the other between two relatively rocking dies while held under tension near to its elastic limit.

The present machine embodies broadly a number of the principles set forth in the combined stretch forming and wipe forming machine disclosed in US. Patent No. 2,514,830, issued July 11, 1950, the basic functions of the latter machine being combined in a new manner for rapid cycle operation.

Various objects and advantages of the invention will become apparent from the following description wherein reference is made to the drawings which illustrate a preferred embodiment of the invention and wherein:

Fig. 1 is a perspective view of the machine embodying the principles of the present invention;

Figs. 2 through 4 are, respectively, a top plan view, :a front elevation, and a right end elevation of the machine :illustrated in Fig. 1;

Fig. 5 is a hydraulic diagram showing the control circuit of the present invention;

Fig. 6 is a diagrammatic top plan viewof the dies of the present invention showing the curvature, of their :side faces about vertical axes; and

, Fig. 7 is a diagrammatic development in a vertical plane of the faces of the dies, showing their curvature about horizontal axes.

dies, they are maintained in the proper registry endwise. A dead center toggle clamp 16 is mounted on the carrier 4 for movement therewith and relative thereto. The toggle clamp 16 is arranged to engage and firmly clarnp one end of a length of stock in fixed position relative to the side face die M. The toggle clamp 16 is operated by a suitable piston and cylinder assemblage 17. The dead center type of operation is provided so that any fluctuation in pressure of the pressure fluid in the supply line, during operation of other piston and cylinder assemblages,

, to be hereinafter described, do not cause a loss of clamp Referring to the drawings, the machine comprises a mainframe 1 having a lateral extension 2 rigid therewith, the frames 1 and extension 2 forming the base of the machine. Mounted on the base are a pair of elongated die carriers, indicated generally at 4 and 5, respectively, which are arranged for swinging about upright pivots 6 and 7, respectively, which are offset from each other endwise of the carriers so that the carriers swing laterally toward and away from each other in overlapping paths.

Mounted on the carrier 4 is a side face male die M I I having a forming face which is curvilinear both about an upright axis and about a horizontal axis. The carrier 5 is in the form of a rail 8 in which a slide 9 is mounted for reciprocation endwise of the rail. on the slide 9 is a complementary side face female die F. As will appear more fully hereinafter, the dies are arranged for relative rolling engagement with each other when the carriers 4 and 5 are concurrently rocked about their respective pivots 6 and toward each other.

-In order to maintain the dies in registry during their relative rolling engagement, a row of suitable detents 11 is provided on the die M and each detent is engageable Carried :7 I

7 while yieldably urged with a complementary notched element 12 on the die F.

plementary gear segments 14 and 15 are provided. Thus, 3

throughout the entire relative rolling movement of the ing pressure. For tensioning and stretching the stock during die forming, a stretch forming piston and cylinder assemblage 20, including a cylinder 21 and a piston 22 having a piston rod 23, is mounted on the frame 1. Also mounted on the frame 1, for sliding movement parallel to the axis of the cylinder 21, is a slide 24 having, at its forward end, a pedestal 25 on which is mounted, for. vertical sliding movement, a slide 26. The slide 26 carries a stock gripping head 27 and clamping cylinder 28 for operating the head for clamping the otherend of the length of stock S in fixed position relative to the head 27. The slide 26 is movable vertically by means of a piston and cylinder assemblage, indicated generally at 29. The assemblage 20 is so arranged that it can maintain tension on the stock during the operation of the dies M and F.

The dies M and F are maintained in relative rolling engagement with each other, from one end to the other, while they are held under predetermined yieldable pressure.

For example, starting at the end adjacent the clamp 16, the dies are brought into contact and are operated in relatively rolling engagement from that end to the opposite end while held in engagement by said yieldable pressure and while the stock is maintained under tension by the assemblage 20.

In order to maintain the dies in yieldable pressure engagement with each other, a piston and cylinder assemblage 30 is provided. The assemblage 30 includes a cylinder 31 which is connected to the base and a piston having a rod 32 which is connected to the rail 8. The piston and cylinder assemblage 30 is mounted for rocking movement about an upright axis 33 parallel to and offset from the axis 7. The assemblage 30 preferably is p of the reversible, hydraulic type so that it can urge the rail 5 to swing about the axis of the pivot 7 toward and away from the carrier 4.

While the pressure fluid supplied to the assemblage 30 can be varied, it is preferable to set it at a constant predetermined pressure and compensate for any changes in pressure which otherwise would occur between the dies F and M, due to the shifting of the position of the instantaneous line of tangency of the dies, by control of the piston and cylinder assemblage for the carrier 4, now to be described.

Mounted on the extension 2 of the base is a forming die piston and cylinder assemblage 35, comprising a cylinder 36 and piston having a rod 37 which is connected pivotally to the carrier 4, as indicated at 38. The cylinder 36 of the assemblage 35 is pivotally mounted on the base of the machine for oscillation about an upright axis 39. The assemblage 35 is preferably a reversible hydraulic piston and cylinder assemblage.

The side forming face of the dies quite often not only are curvilinear endwise about the vertical axes but also about horizontal axes. For example, in Fig. 6, the plan .view of the dies M and F is shown diagrammatically.

In plan, their side faces are curvilinear endwise of the dies about vertical axes, the vertical axes of the side face of the die M being indicated at m, and those of the side face of the die F being indicated at f,.

In Fig. 7, a single development diagram of the side faces on a vertical plane is shown. The development of the side faces of the two,looking at the back of the die M and theforward face of the die F, necessarily coincide and the horizontal axes about which they are curvilinear endwise are the same, and, hence, each is indicated by both m and i Since the die faces are thus curvilinear, it is necessary that the head 28 be lifted and lowered in order to maintain the stock in proper Vertical relation to the dies at the instantaneous line of contact of the dies during the forming operation. This is accomplished by the reversible piston and cylinder assembla'ge 29. For operating this assemblage in proper relation to the dies, a piston and cylinder assemblage 40 is mounted on the extension 2 in fixed position. The assemblage has a cylinder 41 and a piston having a rod 42 to one end of which is connected a cam follower 43. The follower 43 engages a cam 44 which moves in fixed relation to the carrier 4. The cam 44 is so selected, depending upon the rise and fall of the instantaneous line of contact of the particular dies 7, so that it will operate the piston and cylinder assemblage 40 to raise and lower the head 28 to keep the head in proper alignment with the particular height of the instantaneous line of contact above or below the normal starting position thereof at the starting point of contact of the stock and dies.

As mentioned, the preferred method of operating the machine is to maintain a constant pressure in the piston and cylinder assemblage 30, then to maintain the proper pressure between the dies by varying the pressure in the piston and cylinder assemblage 35. For this purpose, there are provided on the machine two control cylinders 50 and 51, respectively, which are operated by cams 52 and 53, respectively, the cam 52 being movable with the carrier 4 and the cam 53 being movable with the carrier 5. The cam 52 is arranged to gradually increase and decrease the pressure at the rod end of the cylinder 36 and the cam 53 is arranged to control venting at the head end of' the'cylinder 36. By the proper correlation of these two control assemblages 50 and 51, by the cams 52 and 53, in a hydraulic circuit, the pressure between'the dies is controlled,

It is necessary that this control be effected inasmuch as the pressure at the instantaneous line of contact of the dies. would otherwise vary quite widely as that line approached or passed across a vertical plane through the axis of the pivot 6 or 7 extending transversely of the dies. Thus, assuming that'the point of contact were a fraction of a thousandth of an inch from such a plane through the axis of the pivot 6, then there would be developed, due to the leverage of the piston and cylinder assemblage 36, a substantially infinite thrust between the dies if the die F could not recede. Again, if the pressure applied by the assemblage 35 were such at all times as 'tourge the carrier '4 to swing in the same direction about the axisof the pivot 6, then, after the instantaneous .lineloff contact passed to the left of the vertical plane, the assemblage 35Jwould be urging the left end of the die M away from the die F. Consequently the direction and amount of pressure in the piston and 'cylinder as- 'semblage 35 must be controlled in order to maintain the desired pressures during the forming operation. v The movements of the carrier 4 and rail are such that the dies can be withdrawn a considerable distance from eaeh fot'her' to pe mi a workpiece to be' dropped out from between the dies M and F when the piece is finished.

A suitable motor driven carrier belt 55 is provided beneath the level of the dies and is positioned to receive' the piece, whenit is released by the clamp 16 and, the head '28, and to transp'ortthe piece out from beneath the dies to. a point of accessibility.

By. locating the stretch forming piston and cylinder assemblage on the frame rather than. on'the slide, the slide gear segments 14 and, 15 are relieved from; all

of the tension stresses applied to the stockby the piston and cylinder assemblage 20. Furthermore, by using this location, the pieces can be formed in which the die faces curve endwise not only in horizontal planes but also in vertical planes, the head 28 being movable to compensate for differences in elevation of the different instantaneous points of contact of the faces above a common datum plane. Furthermore, since the assemblage 20 is on the base, the stock is not held against the face of either one of the dies between the head28 itself and the instantaneous line of contact and, therefore, if the stock has an irregular cross section, it can nevertheless be lifted and lowered without interference by engagement of any shoulders thereon with cavities or shoulders of the die faces between the instantaneous line of contact and the free end of the stock. The swivelling of the piston and cylinder assemblages 35 and 30 compensates for the angularity of the line of thrust thereof as carriers 4 and 5 swing about their respective axes of the pivots 6 and 7.

Since there is considerable overhang in each of the arms in the case of dies of substantial length, sets of complementary relatively sliding rest plates 60 and 61, respectively, are provided, one set on the carrier 4 and the extension 2, and one set on the rail 5 and frame 1. Likewise, suitable complementary hold downplates 62 and 63 are provided on the carrier 4 and extension -2, respectively. 7 After the formation of a piece and its release from the dies, it is preferable to have the slide 9 restored toits normal condition. Since the diesare separated at this time and are not geared together by the detents 11 and notches 12, or by the gear segments 14 and 15, a suitable piston and cylinder assemblage 65 is provided on the rail 8 and is connected to the slide and is operable to restore the slide to starting position.

In operation, assuming the dies are openedby swinging the carrier 4 clockwise about its pivot 6 and the carrier-'5 also clockwise about its pivot 7, apiece of stock is first engaged by the clamp 16 and fastened at one end firmly into position relative to one end of the curvilinear die M. The opposite end of the stock is gripped by the'head 27. The piston and cylinder assemblage 20-is then'operated to tension the stock substantiallyto its elastic limit. While in this condition, pressure fluid is applied to the assemblages 30 and 35 to cause them to swing the carriers concurrently counterclockwise and consequentlytoward each other so as to bring the dies into cooperative relation to each other at their righthand ends, in Fig. l. The application of pressure fluid is continuedso that the instantaneous line of contact moves progressively from the right hand end of the dies to the left hand end in Fig. 1. The carrier4 is forced by the carrier 5 to recede from its original position as the carrier 5 advances. When the instantaneous line of contact passes thepivotalaxis 6, the direction of pressure in the assemblage 35 must be changed so that the assemblage 35 no longer urges the carrier 4 to rotate counterclockwise, as the pressure of the piston and. cylinder assemblage 30, as applied through the carrier 5 and die F, then urges the carrier 4 counterclockwise. This reversal of the pressure in the assemblage 35 is necessary so as to urge the carrier 4 in a clockwise direction so that the end of the die M beyond the axis of the pivot 6 in a direction toward the head 27 is urged toward the carrier Syrather than away therefrom as it would be were the carrier 4 urged to rotate counterclockwise.

Since the machine is to operate in a rapid cycle, the timing must be operative to compensate for the inertia forces occasioned bythe rapid swinging of the heavy carrier A, so that actually the reversal of the assemblage 35 riers through the pivotal axis 6.

After'the dies have been rolledrelative to each other o. t t i end ad ace t. the h ad have formedthe stock entirelyto the end of the dies, then the tension applied by the head 27 is released, the dies are retracted, and the piece is allowed to drop therebetween onto the belt or conveyor 55 which conveys the workpiece to an accessible location.

The feeding of the stock can be done automatically, if desired, since the head 27 is open at one side to permit lateral insertion of the end of the stock.

It is to be noted that the yieldable power means each urges its carrier to rotate in the same direction as the other. However, the carriers, if there is any relative movement, rotate one clockwise and one counterclockwise as one of them is pushed back against the pressure applied by its assemblage. The turning moment imposed by the assemblages on the carriers is unbalanced, one assemblage always applying a little greater moment than the other to elfect the relative rolling movement of the dies.

For semi-automatic control, the circuit illustrated in Fig. may be used. This circuit includes a main pressure linev 70 to which pressure fluid is continuously supplied by a motor-driven hydraulic pump 71.

A branch line 72 leads from the line 70 to a solenoidoperated remote control reversing valve 73-which is connected to opposite ends of the cylinder of the piston and cylinder assemblage 28, which operates the clamping jaws of the head 27. The valve 73 is operable to supply pressure fluid to either end of the cylinder, selectively, and concurrently to connect the other end to a sump.

The branch 72 also is connectable, through a solenoidoperated remote control reversing valve 75, selectively, to either end of the cylinder of the assemblage 17, which operates the clamp 16. The valve 72 is operable to vent the unconnected end of the cylinderto a sump.

Another branch line 77 leads from the line 70 and is connectable by a solenoid-operated remote control reversing valve 78 selectively to opposite ends of the cylinder of the return assemblage 65 of the slide 9. The valve 78 is operable to vent the unconnected end of the cylinder to a sump 79.

Thus, each of the assemblages 28, 17 and 65 may be operated remotely by the operator, or by limit and other automatic switches.

Pressure fluid is supplied through a pressure reducing valve 80 and through a solenoid operated remote control valve 81'to the rod end of the cylinder servo-assemblage 40. The head end of the assemblage 40 is connected to the rod end of the ram hoisting assemblage 29. The head end of the assemblage 29 is connected to a valve 81 and therethrough to a sump 82.

Suitable needle valves 84 and a sequence valve 85 are provided for assuring that the assemblages 29 and 40 and .their circuits normally are maintained filled with pressure fluid at reduced pressure.

Thus the rise and fall of the head 27 is in response to the movement of the piston of the assemblage 40 by the cam 44.

The line 70 also is connectable through a pressure reducing valve 86 and a solenoid operated remote control reversing valve 87 to the opposite ends of the cylinder 21 of stretch forming assemblage 20, selectively. The valve 86 also is operable to connect the unconnected end of the cylinder 21 to a sump 88. A double acting relief valve 89 is interposed between the valve 87 and the rod end of'the cylinder 21.

A two-position, four-way valve' may be, connected between the reducing valve 86 and relief valve 90 for venting them or blocking them so that they operate at their normal pressure setting or at a reduced pressure, selectively.

The next operational control is that of the die carriers 4 and 5.

In the form illustrated, the pressure supplied to the head end of the cylinder 31 of the assemblage 30 for urging the carrier 5 toward the carrier 4 is maintained constant, and the pressure supplied to the cylinder 36 of the assemblage 35 is varied, at times being reversed.

For this purpose, pressure fluid is supplied cd'ntinuously taining constant positive pressure continuously urging the carrier 5 toward the carrier 4.

To assure that the circuit for the assemblage 30 is always filled and operating, the circuit is connected throughv a needle valve 93, check valve 94, and speed control valve withasump. I i

The valve 95 is connected also in the circuit with the head end of the assemblage 35 of the other carrier 4, as now to be described. I

The valve 92 is arranged to connect each branch line 96 and 97 selectively'to the line 70 and to a sump. The line 96 leads to the head end of the assemblage 35 and the line 97 to the rod end. The line 97 is provided between the assemblage 35 and the valve 92 with a check valve 98.

The cam 53 operates a remote control relief valve 98 which is connected to the line 96 between the valve 92 and the head end of the assemblage 35 through a relief valve 99, thus controlling the pressure suppliedto the head end in response to the setting of the cam 53. The head end of the assemblage 35, as it is caused to retract by the pressure of the carrier 5, can vent through the restricted orifice speed control valve 95. As it is extended, it can suck in fluid through the check valve 95a from the line 96.

The line 97 is connected with a line 101 which, through a pressure reducing valve 102, supplies pressure fluid to the rod end of the assemblage 35. The valve 102 is controlled by a remote control relief valve 103 which, in turn, is controlled by the cam 52. Thus the pressure supplied to the rod end of the assemblage 35 is controlled by the cam 52.

A reversible remote control solenoid-operated valve 104 is connected to the line 97 for venting and blocking it, as desired, and a double acting relief valve 105 is connected in the line 97.

For semi-automatic operation, a suitable short-out bar or switch is provided on the die and so arranged that when a workpiece enters the head 27, it causes valves 73 and 75 to operate their associated assemblages 28 and 17 to clamp the ends of the piece.

The operator then operates the valve 87 to supply stretch-forming pressure fluid to the rod end .of the stretch-forming assemblage 20. The line pressure in line '70 is always greater than required for stretching. Consequently, the stretch forming pressure fluid is supplied through the reducing valve 86, the drain of which is connected to a sump and the vent of which is blocked to render the valve active to control the pressure to the assemblage 20.

The blocking of the vent of the reducing valve 86 is etfected by the valve 90 which also blocks the drain of the valve 89 concurrently. As a result, the valve 89 becomes operable for relief only at a maximum preselected pressure which is greater than the pressure for which the valve 86 is set, so that the assembly normally operates under the lower pressure supplied through the valve 86.

As the assemblage 20 elongates, due to wrapping the stock on the die, the valve 87 is set to neutral position, blocking return of pressure fluid from the rod end of the assemblage 20, and valve 90 is energized and operates the drain of the valve 89, making valve 89 activeand causing the vent of the valve 86 to flow to sump, thus setting the valve 86 to minimum value.

Hence, control of valve 89 controls the maximumpressure at the rod end of the assemblage 20 during the stretching cycle.

When valve 92 is in neutral, assemblage 35 has full line pressure blocked in its head end by the valve 92,

The, speedv control valve 95. permits continuous, restricted flow. tokeep the circuit to the assemblage 35 filled and ready for. instantoperation.

Whenvalve9l isoperated, pressure fluid is admitted;

controlled by cam 53, the solenoid of valve 98 being energized during the cycle so that the valve 98 dis charges to sump.

As assembly 35 is being pushed to retracted condition by the carrier 5, the head end sucks'in oil through the valve, 92v by way of the check valve 98a.

As the line of instantaneous contact of the diesF and M pass from right to left past the axis 6 of the carrier 4, the valve 98 is fully opened so that there is no pressure in-the head end of the assemblage 35.

The valve 103', under control of the cam 52, now keeps valve 102 at its lowest setting, so that no pressure fluid'j' is fed to the head end ofthe assemblage 35 through the,

valve102. When the valve 98 starts to unload,,the valve 103, operated by the cam 52, causes the valve 102 to open and supply pressure to the rod end of, the assemblage 35, thus causing itto urge that part of the carrier 4 between its pivot 6 and the head 27 toward the carrier 5.

Assuming a piece has been formed, and the machine is returning to starting position, the jaws of the head 27:

and clamp 16 open. Almost immediately the stretch forming assemblage ltlretracts and the head 27 starts rising, dropping the piece on the conveyor.

The arms and head return to starting position awaiting the feeding of another piece which, when dropped into the jaws of the head 27 and clamp 16,,strikes a short-out bar and'initiates a new cycle.

The starting and stopping positions may be controlled.

by using suitable limit switches, the machine otherwise being controlled by push buttons under the control of an operator.

Having thus described our invention, we claim:

1. In a metal forming machine, a base, a firstelongated die carrier, a second elongated die carrier, said. carriers being arranged side by side, parallel pivots connecting the carriers to the base, respectively, said pivots being.

spaced apart from each. other in a direction generally endwise of the carriers, the pivot of the first carrier being near one end of the first carrier andthe pivot of the second carrier. being near the end of the second car-,

rier opposite from said one. endfof the first carrier, said pivots supporting the carriers for swinging laterally toward andaway from each other, yieldablepower means connected, respectively, to, the carriers and yieldably urging the carriers to swing about their respective pivots toward each other, a slide on the first carrier and slidable endwise thereof, aside face die mounted on the side and extending endwise thereof, a complementary side facedie mounted on the second carrier. and extending endwise thereof and engageable with and disengageable from. the first mentioned side. face die, at least one of said dies having its side face curvilinear endwise for relatively rolling metal forming engagement of the dies with each other progressively from one end toward the other when the dies are pressed together by the carriers with the power means of one of the carriers causing it to apply a greater turning moment on. the other carrier at the instantaneous line of contact ofthedies than the turning momentapplied on the other carrier bythe-power meansof the other carrier, thus causing said one of h Carriers. to swing the other, oft-he carriersabout the pivqt ofsai d.

other, ofthe. carriers against the force. of the power. means,

. of said other of the carriers, gripping meansto secure.

one end of a lengthofstock. in fixedrelation with said complementary die at the end of the second carrier farthest from its pivot, a stretch forming. device. mounted.

on the, base outwardly, generally endwise of the dies,

beyond the end of, said first carrier opposite toitspivot, said stretch forming device-including a' gripping head, for I gripping the other end'of the stock, and being operable to maintain yielding endwise tensioningforce on the stock I during the formingof the stock between the dies, and

means" to control the power applied by the yieldable power means tothe, respective carriers.

2. The structure. according to claim 1 and further in; cluding intermeshing means operatively connected between the slide and saidsecond carrier for synchronizing the relative rolling movement of the dies. 0

3; The structure according toclaim 1 and further in? cluding reversible means for the yieldable power means of thesecond carrier, the first carrier having its free end spaced, in a direction away from its pivot, beyond the pivot, of the second carrier, whereby the yieldable power means-of the second carrier must be reversed asthe instantaneous line of die contact of the dies moves from a position, endwise of the carriers, between the pivots, to a neutral position and thence to final positions which are" beyond both pivots in'a direction toward the free end of the first carrier, and means operable in predetermined relation to the operation of the second carrier for gradually reducing the force applied by the yieldable power means of said second carrier as the instantaneous line of die contact approaches said neutral position, and for-reversing and gradually increasing said last mentioned applied force in the reverse direction in said final positions.

4. The structure according to claim 3, wherein the reversible yieldable powermeans is a fluid pressure operated piston and cylinder assemblage, control means maintaining a predetermined relation to said instantaneous line of contact, a control device operable by said control means, and said control device, in turn, control-- ling theadrnission and discharge of pressure-fluid to said last mentioned assemblage.

5. The structure according toclairn 1 and furtherincludinga power operated returndevice operatively-connected to the slide, and operable to return the slide to starting position'while the diesare disengaged.

6. The structure according to claim 1 wherein one of" said yieldable power means is operative to apply a substantially constant force continuously to its associated carrier andtheother yieldable power means is operable to supply a variable force to its associated carrier.

7. The structure according to claim 1 wherein said second one of the carriers applies the lesser turning= moment of the two carriers.

ReferencesCited in the file of this patent UNITED STATES PATENTS 1,318,968 Claybourn Oct. 14, '1919 1,606,096 Oddie Nov. 9, 1 926. 2,349,520 Ripley May 23, 1944 2,400,151 Kirsch May 14, 1946 2,638,142 Green May 12,1953 2,713,376 Bath July 19., 1 955 2,727,556 Albers Dec. 20,1955 2,806,506 Yurka Sept. 17, 7

FOREIGN PATENTS 27,830 Norway Apr. 16, 1917* 

